A. Brossi et al, Analgetics, Editor, G. DeStevens, Medicinal Chemistry, Vol. 5, Academic Press pp 281-330, report central analgesic effects of 1-(substituted phenyl ethyl)-1,2,3,4-tetrahydroisoquinolines. The optimal analgesic activity was achieved by compounds of the formula (2) ##STR5## in which R.sub.1 is CH.sub.3 and R.sub.2 is Cl or NO.sub.2. Compounds in which R.sub.2 is NH.sub.2 or substituted amino were not reported. The authors also report one compound having a structure corresponding to formula (1), supra, in which R.sub.1 and R.sub.2 are methoxy, R.sub.3 is hydrogen, R.sub.4 is CH.sub.3 and R.sub.5 is .rho.-chloro. This compound is reported not to exhibit analgesic properties.